Gallium arsenide based high frequency circuits are known in the art.
JPL has developed a proprietary planar GaAs Schottky diode process that results in very low parasitic anodes that have cutoff frequencies in the tens of terahertz. This technology enables robust implementation of monolithic mixer and frequency multiplier circuits well into the terahertz frequency range. Using optical and e-beam lithography and conventional epitaxial layer design with innovative usage of GaAs membranes and metal beamleads JPL is able to design high performance terahertz circuits with high fidelity. This has lead to several instruments for space and earth-based platforms.
However, all these mixers use metal waveguide structures for housing. Metal machined structures for RF and LO coupling hampers these mixers to be integrated in multipixel heterodyne array receivers for spectroscopic and imaging applications.
There is a need for mixer circuits that are easier to fabricate and that can be integrated with other circuit elements.